>>12492317Make it dolphin sex instead, two lifting body craft, one with relatively broad wings, more like an SR-71 or Skylon, the other with short flap-wings like Starship for bellyflopping, but a more aircraft like nose. Both vehicles should use a common LOX/CH4 FFSC aerospike, to cut down on necessary maintenance and cleaning. LOX/RP1 hopelessly cokes engines even though it doesn't destroy their metal structure like LOX/LH2 would.
Launch them vertically from a specially designed platform in the gulf, they launch like rockets, booster glides itself back to a landing strip in say Texas or Florida, 2S takes itself the rest of the way to orbit and then returns via bellyflop for a glide in and similarly returns, perhaps even to the same exact strip.
The problem is that at that point it's essentially a more complicated version of a LCH4/LOX TSTO using an FFSC fuel cycle. What I would ask if I were on your design team is "why not just build a normal vertical launch and propulsive landing two stage rocket instead?"
Aerospikes can still be used, you'll have slightly lower TWR but get a substantially higher overall efficiency curve in propellant utilization, or use the same plumbing for both stages but design two powerheads, one a truncated cone aerospike for the 2S and the other a normal converging/diverging bell for the booster, still uses the same preburners and tubromachines but different injectors and nozzles.
Or, if we're going to use an exotic powerhead technology, I'd suggest a rotating pulse detonation engine, the principle has already been proved sound at the small scale, the next step is creating a practically large engine, 25-35% ISP increase without sacrificing TWR would be quite the achievement, and you can combine such a powerhead with an aerospike nozzle to achieve optimal propellant utilization too.
